This paper proposes a high-precision sub-bandgap (sub-BGR) voltage reference (VR) and a temperature-compensated shared-resistive nanoampere current reference(CR) for ultra-low-power Internet of Things (IoT) devices. The CR is used to generate a bipolar junction transistor (BJT) complementary-to-absolute-temperature (CTAT) voltage, which is summed up with a proportional-to-absolute-temperature (PTAT) voltage generated using a summing network of CMOS gate-coupled pairs. The proposed sub-BGR VR and CR are implemented in a 130 nm CMOS process with a total area of 0.03 mm2. Post-layout simulations confirm the excellent performance of the second-order temperature-compensated VR across process corners with a mean temperature coefficient of 19 ppm/◦C. The designed 474 mV VR shows a line regulation of 0.1%/V, with an overall power consumption of 30 nW.